Knock sensor again...

[SpanishJohn]

Hi Dave,

You may be onto something there. Reading the haynes manual, and looking at the schematic, it appears the ECU has to generate a signal in excess of 100V to drive the coils, my money is on this circuit no longer working properly. If this circuit was to become problematic, it would explain all kinds of stuff, even those where the FI light KS fault. In ypur case it would be the CDI unit.

I am in the process of getting/trying a new ECU

Thanks Spanish

 

[silverfox.xx]

The reason behind my thinking is my bike has the same symptoms as yours but is carb fed and doesn't have all the alien do dads the fi bikes have..

As SJ said you do still have a CDI unit.

In fact the F1 has a CDI built into the other engine management do do's

 

[dave boyce]

As SJ said you do still have a CDI unit.

In fact the F1 has a CDI built into the other engine management do do's

With you on the CDI @tu*I'm going to start at the spark plugs and work my way back,I'm hoping its a dodgy lead or coil a new CDI sounds expensive that's when I get the chance bike lives outside and its dark when I get home....Plus my multimeter seems to have grown legs and gone for a walk..

 

[smedly]

Hi Dave,

You may be onto something there. Reading the haynes manual, and looking at the schematic, it appears the ECU has to generate a signal in excess of 100V to drive the coils, my money is on this circuit no longer working properly. If this circuit was to become problematic, it would explain all kinds of stuff, even those where the FI light KS fault. In ypur case it would be the CDI unit.

I am in the process of getting/trying a new ECU

Thanks Spanish

the KS fault had nothing to do with the coils voltage, it was the KS test failing and just that, remember your bike runs fine in safe mode which means the ecu it driving the coils just fine

also I will go take a look but I don't think the ecu produces 100v to drive the coils...........will check

checked and it does, 12v before cranking the engine then peaks to 100v to produce the eht voltage on the secondary side.

 

[dave boyce]

Hi Smedley you sound like a man who knows what his talking about where do you think my problem lays cheers dave

 

[smedly]

what problem mate, I'm confused, I thought this was a spanish thread ??

 

[dave boyce]

what problem mate, I'm confused, I thought this was a spanish thread ??

Same rough patch at 3000 to 4000rpm when the weathers hot smoother when its cold mines a carb model

 

[smedly]

ah right, wouldn't have a clue on a carb bike but and saying the obvious here - air temp = air density = mixture.

my bike runs like a pig when cold at the moment as it requires a rich mixture on a cold engine, my air filter is fooked, just too much air getting in there, runs sweet when warmed up

 

[SpanishJohn]

Hi Dave,

You may be onto something there. Reading the haynes manual, and looking at the schematic, it appears the ECU has to generate a signal in excess of 100V to drive the coils, my money is on this circuit no longer working properly. If this circuit was to become problematic, it would explain all kinds of stuff, even those where the FI light KS fault. In ypur case it would be the CDI unit.

I am in the process of getting/trying a new ECU

Thanks Spanish

My thinking is this. The ECU is solid state right, no moving parts, but nevertheless certain parts will experience more stress than others. In general circuits that handle low voltage, and consume little power are the least stressed, whereas circuits that handle large voltages and generate heat due to power dissipation do experience some stress. The CDI part of the ECU which generates the 100V pulses to the 2.4R coil primary (P = Vsq/R = 10000/2.4 = 4.16KW peak power per coil) will be the most stressed part of the ECU. If anything was to become problematic, this would be it. If that 100V was to drop to 50V, it may explain my problems.

As it turns out I have ordered a new ECU anyway, so can't be arsed to test my theory, and it could be complete tosh. Sounds logical to me though....

Spanish

 

[smedly]

not strictly true, high voltage does not mean high current, the exact opposite actually to an extent, you can measure to 100v output which is a short pulse using a peak voltage measurement meter or ideally a scope, the ecu fault causing the fault 25 KS issue was an audio input to the ecu which from what I can see is a hybrid circuit board mounted on the main pcb yet it failed prob due to a bad solder joint, most of the ecu's function is taking inputs from various sensors then driving the injectors and the spark plugs based on those inputs, it does output a 5v supply to the sensors that need it and that's about it, the simple way to prove if the coil voltage is at fault would be to measure it, the KS fault was more complex but you have a new ecu coming so you will ultimately find out.................tbh I don't think this is your problem as I don't see a relationship with weather and temperature and the coil feed, just my opinion

for the engine to run correctly you need 2 things - fuel and air - the ecu needs to know several things about the air which it reads from sensors, it needs to know the position of various parts of the engine so that it can feed the correct amount of fuel and air mixture to make them combust correctly and at the correct time, it also listens to the engine to allow it some flexibility and to make adjustments to keep everything optimal rather than have a fixed fuel/timing map (safe mode), simple really

 

[SpanishJohn]

not strictly true, high voltage does not mean high current, the exact opposite actually to an extent, you can measure to 100v output which is a short pulse using a peak voltage measurement meter or ideally a scope, the ecu fault causing the fault 25 KS issue was an audio input to the ecu which from what I can see is a hybrid circuit board mounted on the main pcb yet it failed prob due to a bad solder joint, most of the ecu's function is taking inputs from various sensors then driving the injectors and the spark plugs based on those inputs, it does output a 5v supply to the sensors that need it and that's about it, the simple way to prove if the coil voltage is at fault would be to measure it, the KS fault was more complex but you have a new ecu coming so you will ultimately find out.................tbh I don't think this is your problem as I don't see a relationship with weather and temperature and the coil feed, just my opinion

for the engine to run correctly you need 2 things - fuel and air - the ecu needs to know several things about the air which it reads from sensors, it needs to know the position of various parts of the engine so that it can feed the correct amount of fuel and air mixture to make them combust correctly and at the correct time, it also listens to the engine to allow it some flexibility and to make adjustments to keep everything optimal rather than have a fixed fuel/timing map (safe mode), simple really

Not strictly true smedley. You are talking of a sinusoidal signal that is constantly changing. In this case the signal is periodic of width t, period T. For CDI <t> is typically 10-12usec, at 5000rpm <T> will be 24msec. Peak power is Vsq/R = 4.16KW. Average power is Ppk * t/T = 2mW per coil. However, for 12usec every 24msec, the circuit will deliver 4.16KW.

for the engine to run correctly you need 2 things - fuel and air

Wrong: you need three things - fuel, air and a spark capable of igniting the mixture in the current conditions.

I found this article on the net re ignition. v. interesting.

The advantages of solid state are numerous but the big one is : "no moving" parts. This should translate to control and reliability impossible to achieve in any mechanical system. The term "engine tune-up" is nearly meaningless with respect to modern ignition systems. Outside of replacing plugs and inspecting wiring there is not much else to do. More than a few mechanic shops exploit the public misunderstanding of modern engines. Having said that, the disadvantage of electronic ignition is simply reliability.
A desktop computer circuit board should last a LONG time in theory, and yet you know quite clearly it does not sometimes. Ignitions have suffered the same evolution of making electronics that can stand the test of time. Early ignition systems were particularly prone to "component" breakdown. Anyone who has owned an older British sports cars will understand the term "the dark Lord of Lucas" (Lucas Electronics were notorious for their failure).

Solid state components are particularly sensitive to heat, thermal stress, vibration, moisture, and power surges (basically, everything an engine is about). So, great strides have been made to beef up and improve CDI reliability. These include things like:

• Improved cooling and heat sinks
• Epoxy resin or Epoxy-rubber encasing components so they can't get wet
• Using separate ignition modules for each plug (so a single failure won't kill the whole engine). This concept was first exploited in outboards where each plug has a separate "power pack". Power pack failures were a big problem in the outboard industry for awhile and not funny when you are 60 miles from land in a small sport fisherman with 1 engine.
• Heavier duty components that can withstand the heat, vibration, and "duty cycles".
  

I understand what you are saying, and yes it could be a bad solder joint. Who knows. I too did not believe my ECU was at fault, but the more I read the more optimistic I am that my ECU is faulty. Guess I will soon find out.
Spanish

 

[SpanishJohn]

Wow! Page 7. Must be a good thread @tu*

Spanish

 

[smedly]

the ignition pulse does not vary in length it varies in time, good luck with your ecu replacement but in my opinion you're barking up the wrong tree again, the euc does what it does regardless of weather, air density changes and temperature changes the ecu needs to know what the changes are in order to make adjustments, it does this by reading sensors, you said your engine runs fine in safe mode meaning sensor readings are ignored this indicates to me that ecu outputs are not to blame i.e. ignition spark and injector firing - therefore the output side of the ecu is fine, the reason you are changing the ecu (given above) is a possible output failure/problem, I honestly don't see the logic in your thinking

 

[SpanishJohn]

the ignition pulse does not vary in length it varies in time

Thats what I said isn't it?

smedley, in safe mode the ignition does not advance, and the fuel mixture does not lean out so much as the sensors are ignored. This is all good news if you have a weak spark.

I honestly don't see the logic in your thinking.

Spanish

 

[smedly]

go for it mate you've been bang on the money so far, not much left to replace )


PS I saw a black crow this morning........what colour was it lol

 

[dave boyce]

Wow! Page 7. Must be a good thread @tu*

Spanish

Not since "who shot JR?" Have I been so hooked...Whats the ETA for the ECU?@tu*

 

[Duck n Dive]

Not since "who shot JR?" Have I been so hooked...Whats the ETA for the ECU?@tu*

It'll get out of the shower and realise it's been bad dream

 

[SpanishJohn]

Result. ECU fecked @tu*. ECU turns up at 12:30pm and I fitted it immediately and reconnected the KS. Weather mild and sunny (16C) and bone dry conditions (amazing for November eh?). I could tell immediately that it was a different bike. Not even a tingle through 3000rpm :yo:. Did 60miles, some town riding, some motorway riding where I thrashed the arse off it lol (had to slow down once as I had a BMW coupe behind me - though it may be the boys in blue lol). Well chuffed and relieved. Its wierd, but even the tickover sounds different.

Boyce, If I were you I would change the CDI on your bike, seriously. There are a couple at the moment on ebay.

My next problem is working out how to fit the HISS chips to my keys and to my alarm key fob. Many thanks to all who have spent time reading this thread helping me out.

 

[dave boyce]

Result. ECU fecked @tu*. ECU turns up at 12:30pm and I fitted it immediately and reconnected the KS. Weather mild and sunny (16C) and bone dry conditions (amazing for November eh?). I could tell immediately that it was a different bike. Not even a tingle through 3000rpm :yo:. Did 60miles, some town riding, some motorway riding where I thrashed the arse off it lol (had to slow down once as I had a BMW coupe behind me - though it may be the boys in blue lol). Well chuffed and relieved. Its wierd, but even the tickover sounds different.

Boyce, If I were you I would change the CDI on your bike, seriously. There are a couple at the moment on ebay.

My next problem is working out how to fit the HISS chips to my keys and to my alarm key fob. Many thanks to all who have spent time reading this thread helping me out.

At last, pleased you got it sorted,will be working on mine at the weekend fingers crossed...@tu*

 

[SpanishJohn]

Just got back home. Came back from work (40 miles) during shitty peak traffic. Now this was normallt a no-no, as the engine would get hot and trigger terminal vibes. Not this time :yo:. The fan even came one once at a junction, 'cos of the shitty traffic - still no vibes :yo: The only nervous moment was whan I turned the key and the HISS light stayed on. Tweaked the foil around the key and it went off.

I'm keeping the old ECU. I would love to know what part failed. I'm almost certain it was the coil driver as you know. I suspect it would be an easy fix for someone with the right equiptment. I'll keep you posted...

Spanish